Technical Issue Brief II
WWF Paper Prepared for Delegates’ Consideration at POPs INC3
August 1999
PERSISTENT ORGANIC POLLUTANTS:
CRITERIA AND PROCEDURES FOR ADDING NEW
SUBSTANCES TO THE GLOBAL POPS TREATY
persistence in water, the bioaccumulation
potential of the substance based on its log
Kow, and the toxic properties of the
substance.
PART I: INTRODUCTION AND
BACKGROUND
This briefing follows an earlier Technical
Issue Brief on criteria and procedures
published by WWF in March 1999, after
the first meeting of the Criteria Expert
Group (CEG1) held in Bangkok in 1998. It
outlines recommendations for dealing with
several issues which were not resolved at
the second and final meeting of the
Criteria Expert Group (CEG2), which was
held in Vienna in June 1999. Further
international negotiations on these matters
will take place at the third meeting of the
POPs Intergovernmental Negotiating
Committee (INC3) to be held in
September 1999 in Geneva.
Another issue which is likely to discussed
at INC3 is where the precautionary
principle should feature in the treaty. This
was the topic of some heated debate at
CEG2, and it is of vital importance
because it will determine how much
weight is actually given to the
precautionary principle.
Important procedural issues will no doubt
be further debated at INC3. These include
issues such as how other Parties and NGOs
and IGOs can be kept informed of a
substance’s progression in the system once
it has been nominated for consideration as
a POP under the treaty, and how those
other Parties and observers can provide
further data to support (or contradict) a
proposal to designate a substance as a
POP. There is also likely to be some
discussion at INC3 about how to deal with
data gaps on suspect chemicals.
One of the most important areas to be
addressed at INC3 will be the scope of the
treaty, and particularly whether it will
include compounds which undergo
regional rather than global transport.
Another issue relating to the scope of the
treaty, which may be re-opened at the
INC3, is whether organometallic
compounds will be able to be included as
future POPs under the treaty.
WWF’s views on these issues are detailed
below under the following four headings:
scope of the treaty; screening criteria; the
precautionary approach; and procedural
issues. While recommendations are
presented as the issues are addressed in the
text, the complete list of recommendations
are also appended as an annex at the end of
this report.
Some other criteria for identifying future
POPs also need to be finalized. For
example, with regard to the initial
screening criteria to identify future
potential POPs under the treaty, the three
criteria which were not agreed at CEG2
included those relating to the substance’s
1
c) [Environmental transport of a
substance on a global or transregional
scale such that global action is
warranted;]
PART II: SCOPE OF THE TREATY
Long Range Environmental Transport
Some countries want to be able to bring
substances which are transported within
regions under the scope of the treaty,
rather than to restrict it to only those
pollutants which undergo global transport
of several hundred miles. However, other
countries prefer that the treaty embrace
substances which are at least transported
across regional boundaries, but only when
this causes a problem in several regions, or
when regional agreements have not been
able to deal with the problem.
These definitions may look similar in that
all require less than global movement, but
there are significant differences. In
definition (a), proposed by the Swedish
delegate, the substance could be
transported just within regions, although
not just short distances as the transport
would have to be on a regional scale. This
implies distances at least greater than
neighboring countries and potentially up to
regional boundaries. However, as a
clarification, Sweden felt that regional
transport should include substances which
led to environmental exposure at distances
more than 100 kilometers from the source
of release. In this option, even if the
substance did not cross regional
boundaries, but it was transported within
several regions, the substance would best
be controlled by taking global action. This
definition could potentially allow countries
access to global legislation to control the
polluting activities of countries up-river
from them.
The EU countries include the main
proponents for including regional transport
and highlighted that according to the
Governing Council decision 19/13C,
paragraph 9, the “potential for regional and
global transport” should be taken into
account. The need to consider regional and
global transport is also repeated in the
terms of reference of the CEG.
This matter will need to be resolved by the
INC. By the end of the CEG, three
definitions of long range environmental
transport were in square brackets,
indicating lack of consensus (paragraph
51, UNEP/POPS/INC/CEG/2/3):
In definitions (b) and (c) the substance
must move beyond one region. In
definition (b) action could focus on
substances causing transregional problems
if regional action by itself was not
sufficient, for any reason. It could, for
example, include cases where bilateral
regional action was attempted but was not
successful because one region was not
willing to take action. Alternatively, it
could require action if two or more regions
were involved, and one or more of them
did not have the domestic legislative
capabilities or lacked the necessary
a) [Environmental transport of a
substance on at least a regional scale
occurring in different regions of the
world;]
b) [Environmental transport of a
substance globally or trans-regionally
and at a distance where regional action
is not sufficient alone to address the
problem;]
2
regulatory authorities to take action. In
definition (c), action within the global
treaty would only take place if multiple
regions were involved, and they were
willing to take action on a global scale.
This definition implies the involvement of
more than two regions.
there were problems in some other areas. It
was argued that regional problems would
be better addressed at a more local scale,
as required by the principle of subsidiarity.
The case of nonyl phenol ethoxylates was
used as an example, since the EU might be
considering regulating these substances,
but they were not considered to be a
serious problem in the U.S.
Arguing in support of including substances
with just regional transport, the
Netherlands delegate used the analogy of
the “well” theory, noting that it was best to
cover the well before the child fell in. He
noted that many of the chemicals currently
ear-marked for global controls had been in
use for around 50 years and during this
time their ability to be transported globally
had gradually become apparent. However,
a chemical which had been used for a
shorter period and which had already
become a regional problem, might, in time,
become a global problem - but it was
better to take action before it did. The
PBDEs (polybrominated diphenyl ethers)
were used as an example, since these
flame retardants are now found in most
areas of the globe, but it would be difficult
to prove that there was global transfer
because they are so widely used and goods
containing them are found throughout the
globe. To support this argument it was
noted that with DDT it had only become
absolutely clear that global transfer had
occurred after it had been banned in
certain areas and subsequently found in
areas remote from existing sources.
Austria raised a pertinent question as to
what was the usual definition of a region.
It was suggested that it would be up to the
INC to agree on such a definition, although
it was thought to be perhaps smaller that
the five regions of the UN.
WWF Recommendation No. 1:
Substances causing regional problems
in several areas should be able to be
covered under the treaty, even if there is
no proof of environmental transport on
a global scale.
Organo-metallic Substances
Organic compounds are generally defined
in chemistry textbooks as compounds that
contain carbon and in some cases other
elements as well. If this definition were to
be embraced in the treaty, then organometal compounds could come within its
remit. Consistent with this approach, the
final report of CEG2 stated that it was
“agreed that organo-metallic chemicals
were organic chemicals and therefore fell
within the scope of the future convention”
(UNEP/POPS/INC/CEG/2/3). Provided
this issue is not re-opened during INC
consideration, this will stand as the official
guidance, such that organo-metallic
compounds can be proposed for inclusion
in the treaty.
The U.S. was against allowing pollutants
to be covered by the global treaty if the
substances were only causing regional
problems, arguing that it would infringe on
national sovereignty if a country were to
lose the ability to use a chemical with
which it had no problems just because
3
In support of the arguments for the value
of 2 months WWF notes the following:
WWF Recommendation No. 2: Organometal compounds should be able to be
added to the treaty in future.
1. Data shown in Table 2, page 15
indicate that it is not strictly correct
that the water half-life data for all
existing POPs far exceeds 6 months.
2. Since water is a transport medium, the
half-life should be more comparable to
the half life in the other transport
medium, namely, air. As an
approximate rule, which is used in the
prediction of oil spills, water in the
upper few meters of the water column
moves at 2.5 - 3.0% (i.e. 1:33 or 1:40)
of the wind speed, and lipophilic (fatloving) pollutants implicated in global
transfer may be found in the surface
micro-layer. Therefore, a pollutant
which traveled two days in air might
be expected to travel the same distance
in 66-80 days in the upper layers of the
ocean. This ratio is noted in several
publications including the UK Ministry
of Defence Hydrographic Department
publication on Ocean Passages for the
World (1973) which puts forward an
average empirical value of about 1:40
for the ratio of the speed of the surface
current and the speed of the wind
responsible.
3. The UN ECE POP protocol lays down
a half-life in water of greater than 2
months as a criterion.
4. Persistence can vary according to
climatic conditions. For example,
chemicals are liable to persist longer in
colder countries, where the summer
season is short, because this leads to
reduced breakdown in water
(hydrolysis). Similarly, chemicals may
persist longer in the more acidic waters
that are found in Finland. For a POP,
PART III: SCREENING CRITERIA
The criteria for identifying future POPs
will be crucial to determining the
effectiveness of the treaty in regulating
dangerous chemicals beyond the initially
agreed dozen substances.
Listed in Table 1, page 14 are the
screening criteria which CEG2 has
proposed that a substance must fulfil
before it can progress to a more detailed
evaluation as to whether it might warrant
consideration for inclusion in the treaty.
The numerical criteria are to be applied in
a transparent, flexible, and integrated way.
Therefore, the door will be left open for
expert judgement to play an important
role.
Persistence in Water
Agreement was not reached at CEG2 as to
whether a value of 2 months or more vs. 6
months or more should be chosen as the
screening criteria for persistence in water.
Countries proposing the adoption of a 6
months or more value for persistence in
water presented a bullet-point list of
reasons to support that longer time period
(reproduced in Box 1 below). Many other
countries, including those of the EU,
favored the adoption of a 2 month value
and their reasons are also reproduced in
Box 1. WWF supports the two month
value for the reasons listed.
4
Box 1: Written arguments for water half-life values as submitted by experts at CEG2
“Preliminary arguments for a half-life in water of 6 months

Water half-life data for existing POPs far exceeds 6 months.

Data on soil and water half-life show that they are approximately the same (Boethling
et al., Federle et al.). Sediment and water tests indicate that these half-lives in the two
compartments are inexorably linked.

Experimental data under laboratory conditions show that the half-life in water is longer
than the half-life in soil (water-covered soil - Japanese data).

The 2 month proposal is inherently based on a transport/dissipation argument – general
definition of persistence relates to degradation not dissipation.

Although the EU guidance document argues that sorption would make the substance
unavailable for degradation and thus support different half-life criteria, recent
experimental data indicate that sorbed substances can be degraded.

Field data for ocean transport of POPs indicates that movement is much slower than in
air (i.e., several order of magnitude) - AMAP and SETAC workshop.

Risk Assessors consider a half-life of greater than 6 months to be persistent.
Practical aspects

Precaution should not be applied to selection of criteria values but rather in risk
management phase.

Consistent with global priorities - This is a Convention for those substances warranting
international action because they cannot be controlled by local or regional action.

6 months will capture fewer substances; therefore there will be less need to prioritise
chemicals for review or action ensuring greater possibility that global management will
occur.

6 month half life will allow flexibility in application of the guideline based on data
quality and representativeness.” (UNEP/POPS/INC/CEG/2/CRP.15)
The arguments in favor of the value of 2 months were submitted as follows:
“Preliminary argument for a half-life in water of 2 months
The half-life in water should be 2 months because of the following reasons:

For many substances, the degradation in water and in soil and sediment is roughly
similar, but for lipophilic substances, like POPs, which sorb to soil or sediment, and
are less bioavailable, are likely to have longer half-lives in soil and sediment than in
water.

This has been already adopted in international regulatory evaluation procedures.

Water is, in contrast to soil and sediment, a mobile transport medium like air.

During transport in water, aquatic organisms are exposed to the POP. The velocity of
transport in water is significantly slower than in air. A criteria value of 2 months for
half-life in water seems to correspond well with the proposed half-life in air of 2 days.”
5
(UNEP/POPS/INC/CEG/2/CRP.15)
6
compound’s concentration in octanol to its
concentration in water, the more fat
soluble the compound and the more likely
it is to bioconcentrate. Thus, the log Kow is
used as an indication of a chemical’s
potential for bioconcentration. The
bioconcentration factor or BCF is based on
laboratory studies and is defined as “the
concentration of a substance in or
adsorbed on an organism or specified
tissues thereof divided by the
concentration of the substance in the
surrounding medium at steady state”
(UNEP/POPS/INC/CEG/2/3). When the
ratio is derived from accumulation through
both the medium and the food chain, it is
called the bioaccumulation factor (BAF)
and this is generally based on field studies.
The BAF is defined as “the concentration
of a substance in an organism divided by
the concentration of the substance in the
surrounding medium”
(UNEP/POPS/INC/CEG/2/3). In
determining what weight to put on such
data, BAFs are generally preferred to
BCFs because BCFs are only evaluating
partial bioaccumulation.
the persistence in the receiving
environment should be an important
consideration, and this should be taken
into account in determining screening
values for half-lives. The CEG
included a footnote to the effect that
the conditions and methods of
measurement of half-lives need to be
defined. Nevertheless, because
substances may persist longer than
predicted in ecosystems in colder
regions and may be bound to particles,
it is argued that opting for the least
restrictive value would be the best
option.
5. Precaution should be applied to the
selection of criteria values in order that
suspected substances can be
considered at greater depth at the risk
profile stage.
6. If a 2 month value is adopted, more
substances will potentially be captured.
If several substances are deemed to
possess the characteristics of a POP for
possible inclusion under the treaty,
then resource limitations will dictate
that the most problematic ones will
receive priority consideration.
Bioaccumulation Potential Based
on Log Kow
It is much simpler to perform tests on
substances to obtain log Kow values as
compared to undertaking tests to obtain
BCFs. The log Kow is thus a useful
screening tool. However, at the risk profile
stage, measured BCFs or BAFs must be
provided because log Kow values are not
always reliable indicators of the ability to
bioconcentrate.
The Kow or octanol-water partition
coefficient is a way of measuring a
substance’s propensity to bioconcentrate. It
relies on dissolving the substance in a
mixture of water and a solvent called
octanol. The greater the ratio of the
At CEG2, opinions were still divided as to
whether a log Kow value of 4 or 5 should
be used at the initial screening stage. The
EU countries put forward detailed
arguments in favor of adopting a log Kow
value of 4 and WWF supports this
WWF Recommendation No. 3: The
criterion of a half-life in water of
greater than 2 months should be chosen
in preference to a half-life of greater
than 6 months.
7
Because of the uncertain measurement and
uncertain predictive value of log Kow and
the fact that only actual bioaccumulation
data or BCF studies will be relied upon in
the final analysis, the lower proposed
criterion of a log Kow of 4 or more should
be accepted. The adoption of a log Kow
screening criterion of 4 could also be an
important indication of whether there is a
political will to actually test some
substances for their potential to
bioconcentrate, and therefore how far the
treaty will be of use in future to control
substances which might be predicted to
cause harm. To date, only a very small
proportion of substances have been tested
for their potential to bioconcentrate.
Therefore, the more inclusive lower value
should be adopted at the screening stage.
The arguments put forward by national
experts at CEG2 in support of each of the
values under consideration are reproduced
in Box 2.
position. WWF Recommendation No. 4:
For screening a log Kow value of 4
should be adopted in preference to a log
Kow of 5.
This recommendation is based on several
reasons. First, it is well known that log Kow
values are a poor tool to predict the
bioaccumulation potential of substance,
and therefore at the evaluation stage, a log
Kow value will not be sufficient. Before a
substance can be added to the treaty there
must be a BCF study or BAFs which
confirm the predicted potential for
bioaccumulation. However, at the
screening stage, it would certainly be
unwise to dismiss substances with
recorded log Kow values of less than 5
because a few substances with Kow values
of considerably less than 5 appear to be
extensively bioaccumulated. For example,
some organotin compounds with log Kow
values of around 3.3-3.6 have been found
to have BCFs over 5000. Similarly,
lindane has a log Kow in the range 3.2-3.7,
and yet field measurements for bream in
the River Elbe suggest a BCF of 10,00050,000 and a BCF of 26,198 was found in
one study for the common mussel.
Although the use of a log Kow of 5 might
be seen to be a useful screen to indicate
those substances which are likely to have a
BCF over 5000, it can not be relied upon
to pick out all such substances. There may
also be substantial errors in some of the
values put forward for log Kow. For
example, chlordane has a BCF greater than
5000, yet in the Data Bank of the U.S.
National Library of Medicine, a log Kow of
2.78 is quoted, which is significantly at
odds with the value of 6.00 reported by
other workers.
With regard to data availability, it is
interesting to note that even for chemicals
traded in high volumes there is a great lack
of actual measured data on their ability to
bioconcentrate or bioaccumulate. The U.S.
delegation presented details of the
availability of test data for some 4620
chemicals of which 4103 were traded in
high volumes. This showed that for 66%
of these chemicals there were no available
data on their BCFs or BAFs, and for 64%
there were no log Kow values. Similarly,
the German delegation found that even
25% of 2217 “new” substances (notified
since 1981 and with a EU production level
of more than .99 tonnes) did not have log
Kow values. Interestingly, of the substances
for which Kow values were available and
for which there were data showing that
they were not inherently biodegradable, 14
8
Box 2: Written arguments for log Kow values as submitted by experts at CEG2
“Preliminary arguments for a log Kow of 5

Japanese data indicate
BCF
> 5000
 5000
Total
Log Kow
4 to < 5
0
22
22
Log Kow
5
12
8
20



Consistent with all other POPs international treaties of a regional scale
The existing POPs have log Kow > 5
The relationships between log Kow and BCF show that log Kow of 5 is equivalent to BCF of
5000 – logical connection. (Log Kow of 4 is equivalent to a BCF of approx. 500.)

BCF must be greater than 5000, and log Kow greater than 5 for biomagnification to occur.
Practical aspects

Precaution should not be applied to selection of criteria values but rather in risk management
phase.

Consistent with global priorities - This is a Convention for those substances warranting
international action because they cannot be controlled by local or regional action.

Log Kow of 5 will capture fewer substances; therefore there will be less need to prioritize
chemicals for review or action ensuring greater possibility that global management will occur.

Log Kow of 5 allows for flexible application of guideline based on data quality and
representativeness” (UNEP/POPS/INC/CEG/2/CRP.15).
The arguments put forward in support of a log Kow of 4 were as follows:
“Preliminary arguments for a log Kow of 4
A log Kow value of 4 is needed only for the screening stage in cases when valid experimental
BCF/BAF data are missing. It is not sufficient for the evaluation stage. Thus a log Kow of 4 is an
incentive to generate lacking measured BCF/BAF data. At the screening stage it is important that the
log Kow value is set sufficiently low so that its application will include all substances which
bioaccumulate to an extent within the scope of the Convention and not to exclude potentially
bioaccumulating substances.
Bioaccumulation of substances in living organisms is dependent on the species and the environmental
conditions; also, log Kow values may vary according to the methods of measurement. Even though
generally accepted correlations between log Kow and BCF in fish have been established, it would be
unwise to use the average correlation equations as a trigger. This may especially be the case when
bioaccumulation concerns other aquatic species than fish. It should furthermore be recognized that
there are even some already acknowledged POPs which are significantly more bioaccumulative in
aquatic species than predicted by their log Kow values” (UNEP/POPS/INC/CEG/2/CRP.15).
9
had a log Kow greater than 4, and 7 had a
log Kow greater than 5. However, data to
determine whether these substances had a
water half-life of 2 or 6 months were not
available. This shows that many of the data
which are essential for identifying POPs
are just not available, even for the newer
chemicals on the market. Therefore, there
is a need for national and international
regulatory regimes to address this data
deficit.
However, others felt that agreed text
should not be re-discussed. Therefore, the
final proposal from the CEG was to leave
the heading in square brackets to allow for
further debate at the INC. The currently
proposed text for this section of Annex D
is therefore:
“(e) [Reasons for concern] [Adverse
effects]: Evidence that toxicity or
ecotoxicity data indicate the potential
for damage to human health or the
environment. This evidence [needs
to] [should] [, where possible]
include comparison of toxicity or
ecotoxicity data with the detected or
predicted levels of a substance
resulting or anticipated from longrange environmental transport.”
WWF Recommendation No. 5:
Mandatory national and international
testing programs should be instigated to
determine the ability of substances to
bioconcentrate and persist in the
environment. Such testing programs
should be tailored to determine whether
substances meet the criteria necessary to
be considered POPs under the treaty.
To this end, organizations such as the
International Standards Organization
(ISO) and the Organization for
Economic Cooperation and
Development (OECD) should be
encouraged to develop and improve
relevant test methods.
There are three main issues here of
concern. First, the extensive data which
may be required could deter some
countries from nominating a substance.
Second, the wording may imply a high
burden of proof. For example, it could be
construed that in order for there to be
potential for damage, actual or predicted
levels in far away locations must exceed
currently accepted lowest observable effect
levels (LOELs) or no observable effect
levels (NOELs). Third, if only
toxicological and ecotoxicological effects
are able to be considered, it could mean,
for example, that if fish in a remote area
were contaminated such that people no
longer ate them, this would not be
sufficient for this criteria to be met.
Toxic Properties of the Substance
At the first meeting of the CEG, delegates
agreed that before a substance could be
considered to meet the screening criteria,
there should be some “reasons for
concern” with regard to the toxicity of the
substance. At CEG2, several experts
proposed that the reasons for concern
should relate to all the criteria, namely
persistence, bioaccumulation, and potential
for long range environmental transport, as
well as the toxicity of the substance. They
suggested that the heading for this
paragraph should be “adverse effects.”
With regard to the first issue, it needs to be
recognized that making the data
requirements too onerous might deter
some countries, particularly developing
countries, from nominating substances.
10
This would be a regrettable outcome, as
global legislation should be able to achieve
its aims and encourage participation from
all nations. It could be argued that it would
be very difficult for all countries to
provide data comparing the current
toxicity or ecotoxicity data with either
modeling results predicting levels in far
away places or with the detected levels
found in far away locations. The
information listed in paragraph (e), quoted
above, must be submitted by a country
proposing that a substance should be
considered for inclusion in the treaty.
More detailed evaluation will be needed at
the evaluation stage. Therefore, any
comparisons of toxicity data with actual or
predicted levels in locations remote from
the sources should not be mandatory. The
colloquial meaning of the wording “where
possible” should be retained, although this
might be better phrased as, “countries
wishing to provide comparison of toxicity
or ecotoxicity data with the detected or
predicted levels of a substance resulting or
anticipated from long-range environmental
transport are encouraged to do so.”
However, regulatory action should not
have to wait until a substance, by itself, is
found in the environment at levels which
might be predicted to cause harm. This
approach is necessary because it is likely
that many substances could act together to
cause the threshold for effects to be
exceeded. It is usually impossible to
accurately predict the long-term effects on
higher predators and man from a few
shorter-term tests on a few selected
species. Therefore, it is important that a
precautionary approach is taken when
evaluating the potential for toxicity.
Consistent with this lower threshold, the
Tolerable Daily Intakes of substances such
as dioxins and PCBs have had to be
revised downwards over time as new
information on their effects has come to
light.
Global regulatory action should be able to
be taken if the substance is believed to
exert its effects via certain biochemical
modes of action which give cause for
concern, and that action should be taken
even if the measured or predicted levels in
the remote environment are below those
known to cause harm at the present time. If
the substance is biologically active, then at
the screening stage, available toxicity data
should only be used to prioritize the
progression of substances to the more
detailed evaluation stage. Recognizing that
many countries are adamant that
substantial concerns about toxicity must
already be manifest, there is a need to
clarify the burden of proof. WWF
Recommendation No. 7: The substance
should be able to meet the screening
criteria if it is believed to exert effects
via certain biochemical modes of action
which give cause for concern.
WWF Recommendation No. 6: At the
screening stage, comparison of toxicity
or ecotoxicity data with actual or
predicted levels in far away locations
should not be mandatory.
With regard to the burden of proof, the
wording might imply that the predicted
environmental concentration (PEC) in the
remote area must be compared to the
predicted no effect concentration (PNEC),
and be shown to be likely to exceed it,
before it is accepted that there is evidence
indicating potential for damage.
11
passes on to the review stage. The purpose
of this is,
Regulatory action should not have to
wait until there are data showing that
the substance has the potential to
exceed, in the remote environment, the
levels currently known to cause damage
human health or the environment.
“to evaluate whether the substance is
likely to lead to significant adverse
human health and/or environmental
effects as a result of its long-range
environmental transport, such that
global action is warranted.”
Another concern with regard to paragraph
1(e) relating to the toxicity of the
substance is the narrowness of the reasons
for concern. If only toxicological or
ecotoxicological data can be considered,
this would potentially exclude effects on
fishing industries, unless it could be shown
that the fish were actually likely to be
damaged. For example, it could be
envisaged that fish in a remote region
might become contaminated such that
people no longer wanted to eat them,
which would have serious economic and
social implications for indigenous people.
However, the fish might not show signs of
damage, and in fact their numbers may
increase as people would no longer be
eating them. Similarly, the people
themselves would not be harmed because
they no longer ate the fish, and the levels
might be below those known to cause
effects in humans.
However, the effects of long-term
exposure to low levels of pollutants may
take many years to become apparent.
Therefore, there is a need to ensure that the
precautionary approach is taken when
considering the likelihood of adverse
effects. The precautionary approach (as
laid down in Principle 15 of the Rio
Declaration) states that,
“where there are threats of serious or
irreversible damage, lack of full
scientific certainty shall not be used as
a reason for postponing cost-effective
measures to prevent environmental
degradation.”
The weight that is given to the
precautionary approach will depend on
where reference is made to it in the treaty.
The U.S. delegation believes that it should
only be in the preamble. However, in the
preamble it will carry far less weight than
if it was in the main body of the text,
which is where some delegates, including
those from most of the EU countries, feel
it would be more appropriate. Norway
would like the precautionary approach to
be explicitly referred to in the criteria for
identifying additional POPs.
WWF Recommendation No. 8: At the
screening stage, even in the absence of
convincing toxicological data, a
substance should be able to meet the
criteria if adverse social or economic
impacts have occurred due to concerns
about the toxicity of the substance.
PART IV: THE PRECAUTIONARY
APPROACH
WWF Recommendation No. 9: The
precautionary approach should relate to
all decisions taken as to whether or not
If the substance is judged to have met the
criteria of the initial screening stage then it
12
expertise with regard to those proposals.
This would be in line with Principle 10 of
the 1992 United Nations Conference on
Environment and Development Rio
Declaration, which states that
“environmental issues are best handled
with the participation of all concerned
citizens, at the relevant level,” and that
“each individual shall have … the
opportunity to participate in decisionmaking processes.”
a proposed substance meets the
screening criteria and the requirements
for listing under the treaty, and the risk
management objectives of the treaty. It
should therefore be stated in the main
body of the treaty text, in addition to
being in the preamble.
At the review stage, some testing of the
substance (e.g. BCF) may be required, and
hence there is a real need to ensure that
such tests are undertaken in a timely
fashion. Where tests are required, major
producers should be contacted and
informed of the situation in order to allow
them to carry out the necessary testing, but
if these are not undertaken within the time
allotted, then the worst case should be
assumed. The times allotted for various
tests should be prescribed at the outset of
the treaty by the Secretariat or a Technical
Group. Such measures are needed if the
treaty is to be seen as an effective tool for
dealing with internationally suspect
chemicals in a timely manner.
WWF Recommendation No. 11:
Governments should put in place
mechanisms to enable members of the
public and public interest/
environmental groups to make
suggestions as to potential candidate
substances for nomination.
Assessing the Proposal and the Need for
Full Transparency
The Secretariat assesses whether the
proposal contains all the data elements
necessary for the Persistent Organic
Pollutant Review Committee to evaluate
whether the screening criteria have been
met. In the event that the proposal is
lacking certain necessary information, the
Secretariat informs the Party or Parties
proposing the substance. WWF concurs
with the CEG that Parties and observers
should be informed if the POP Review
Committee considers that the screening
criteria have not been met. There is also a
need for transparency, so that the reasons
for setting aside a proposal can be
ascertained. WWF Recommendation No.
12: If a proposal to list a substance does
not contain the information required at
the screening stage, the Secretariat
should inform all the Parties and
WWF Recommendation No. 10: After
an appropriate time period lack of data
should be dealt with by using the worst
case scenario.
PART V: PROCEDURAL ISSUES
Nomination of Substances as Potential
Future POPs
The CEG suggested that only a Party or
Parties (that is countries which are a party
to the treaty) would be able to propose a
substance for screening and evaluation as
to whether it should be considered for
global action. However, there is a need to
enable the public to contribute views and
13
evaluation stage because such
considerations should not cloud sound
scientific judgment as to whether a
substance should be considered to be a
POP requiring global action. However,
there are extremely important socioeconomic considerations, and those must
be thoroughly evaluated once a POP has
met the evaluation criteria. Clearly socioeconomic considerations may dictate the
need for time-limited derogations for the
use of a particular POP in prescribed
circumstances in certain areas. Even in
those situations, though, for the longerterm WWF maintains that ultimate phase
out is necessary due to the inherent
characteristics of POPs.
observers and indicate which data were
missing in order that assistance can be
provided in filling the data gaps.
There is also a need for transparency in the
evaluation of the risk profile. In the event
that the POP Review Committee decides
that a proposal shall not proceed, this
document and a summary of the reasons
why the proposal has been set aside should
be available to the public. Similarly, the
report to the Conference of the Parties
(COP), which makes a recommendation as
to whether or not the substance should be
considered for listing based on the risk
profile and the risk management
evaluation, should be communicated to all
Parties and observers and made available
to the public.
WWF Recommendation No. 14:
Socioeconomic factors are important for
determining appropriate time scales for
the elimination of a POP, but should be
given consideration only after the
evaluation stage has determined that the
substance is a candidate POP under the
treaty.
WWF Recommendation No. 13: At all
stages in the process of establishing
whether or not a proposed substance
should be listed under the treaty, there
should be full transparency of the
decision making process. A summary of
the reasons for the decisions taken, or
recommendations made by the POP
Review Committee, and all written
documentation supporting such
decisions or recommendations should be
available to Parties, observers, and the
public. When available, the report to the
COP (making a recommendation as to
whether or not the substance should be
considered for listing under the treaty),
should be communicated to all Parties
and observers.
Socio-economic Considerations
WWF concurs with the output of CEG2
which suggests that socio-economic
aspects should not play a role in the
14
TABLE 1: INITIAL SCREENING CRITERIA FOR A POTENTIAL POP
(Taken from the final report of CEG2 (UNEP/POPS/INC/CEG/2/3)
A future POP would be expected to meet at least one of the criterion laid down in each column. This
table is therefore to be read downwards only.
PERSISTENCE
BIOACCUMULATION
Half life in water is
[>2 months]
[>6 months]
BCF or BAF in aquatic
species >5000
...or
...or
Half-life in soils
>6 months
In the absence of BCF/BAF
data
log Kow > [4][5]
...or
...or
Half-life in
sediments
>6 months
Evidence that a substance
presents other reasons for
concern, such as high bioaccumulation in other
species or high toxicity or
ecotoxicity.
...or
...or
Evidence that the
substance is
otherwise
sufficiently
persistent to be of
concern within the
scope of the
Convention.
Monitoring data in biota
indicating that the bioaccumulation potential of the
substance is sufficient to be
of concern within the scope
of the Convention.
15
POTENTIAL FOR
LONG RANGE
TRANSPORT
TOXICITY
CONCERNS
Measured levels of
potential concern in
locations distant from
the sources of release of
the substance
...or
[Reasons for
concern] [Adverse
effects] Evidence
that toxicity or
ecotoxicity data
indicate the potential
for damage to human
health or the
environment. This
evidence [needs
to][should][,where
possible,] include
comparison of
toxicity and
ecotoxicity data with
the detected or
predicted levels of a
substance resulting
or anticipated from
long-range
environmental
transport.
Monitoring data
showing that long-range
environmental transport
of the substance, with
the potential for transfer
to a receiving
environment, may have
occurred via air or water
or migratory species
... or
Environmental fate
properties and/or model
results that demonstrate
the potential for long
range environmental
transport, ... with the
potential to transfer to a
receiving environment in
locations distant from
the sources of release of
the substance. For
substances that migrate
significantly through air,
the air half-life should
be > 2 days.
TABLE 2: PERSISTENCE OF THE TWELVE POPS
Taken from International Council of Chemical Associations (ICCA) paper 7/97 (revised 29 April 1998)
Procedure for identifying further POP candidate substances for international action.
Substance
Half-life in
air
Half-life in
water
(temperate
climate)
Half-life in
soil
(temperate
climate)
Half-life in
sediment
(temperate
climate)
DDT
2 days
> 1 year
> 15 years
no data
Aldrin
< 9.1 hours
< 590 days
approximately
5 years
no data
Dieldrin
< 40.5 hours
> 2 years
> 2 years
no data
Endrin
1.45 hours
> 112 days
up to 12 years
-
Chlordane
< 51.7 hours
> 4 years
approximately
1 year
no data
Heptachlor
No data
< 1 day
120-240 days
no data
HCB
< 4.3 years
> 100 years
> 2.7 years
Mirex
No data
> 10 hours
> 600 years
Toxaphene
< 5 days
20 years
10 years
-
PCBs
3 - 21 days
> 4.9 days
> 40 days
-
Dioxins (2,3,7,8And 1,2,3,4-TCDD)
around 9 days
> 5 years
10 years
> 1 year
Furans (2,3,7,8-)
7 days
> 15.5 days
no data
no data
16
> 600 years
TABLE 3: LOG KOW VALUES AND BIOACCUMULATION DATA AND VAPOR PRESSURE
OF THE 12 POPS
Taken from International Council of Chemical Associations (ICCA) paper 7/97 (revised 29 April 1998)
Procedure for identifying further POP candidate substances for international action.
Substance
Log Kow
BCF (wet)
Vapor pressure
(Pa)4
DDT and metabolites
6.5
3,900 to 91,000
0.00002
Aldrin
5.1 - 7.4
10,710
0.01
Dieldrin
5.4
2,100-34,700
0.005
Endrin
5.2
4,200-49,800
0.003
Chlordane
6.0
7,100-37,800
0.0011
Heptachlor
4.3 - 5.3
1,100-20,000
0.01
HCB
5.9
7,800-22,000
0.0015
Mirex
7.1
18,100-20,400
0.0001
Toxaphene
> 5.0
19,500-70,800
0.002
PCBs
6.9
57,000-800,000
0.2 to 0.00003
Dioxins (2,3,7,8-)
7.0
7,900-344,000
0.12 to 1.1E-10
(decreases with
increasing chlorination
Furans (2,3,7,8-)
5.82
2,570-66,000
0.00039-5.0E-10
(decreases with
increasing chlorination)
17
United Nations Environment Programme Criteria
Expert Group for Persistent Organic Pollutants,
Second Session, Vienna, 14 - 18th June 1999,
Submission by the Delegation of Germany, POPs
data availability study regarding new chemicals.
UNEP/POPS/INC/CEG/2/CRP.3. 14 June 1999.
SOURCES
International POPs Elimination Network (IPEN).
Background statement and POPs elimination
platform. See www.worldwildlife.org/toxics and
access POPs section.
United Nations Environment Programme Criteria
Expert Group for Persistent Organic Pollutants,
Second Session, Vienna, 14 - 18th June 1999,
Submission by the Delegation of The United States
of America. POPs data availability analysis (draft).
UNEP/POPS/INC/CEG/2/CRP.8. 14 June 1999.
Persistent Organic Pollutants: Criteria and
Procedures for Adding New Substances to the
Global POPs Treaty, Technical Issue Brief, World
Wildlife Fund, March 1999.
UK Ministry of Defence Hydrographic Department.
Ocean Passages for the World, 3rd edition, Taunton,
Somerset, Ministry of Defence, 1973.
United Nations Environment Programme Criteria
Expert Group for Persistent Organic Pollutants,
Second Session, Vienna, 14 - 18th June 1999,
Views expressed during discussions by the contact
group on Annex D, Annex E, and Working
Definitions. UNEP/POPS/INC/CEG/2/CRP.15. 18
June 1999
United Nations Environment Programme Criteria
Expert Group for Persistent Organic Pollutants,
Second Session, Vienna, 14 - 18th June 1999,
Comments submitted by Governments on the report
of the Criteria Expert Group on the work of its first
session. UNEP/POPS/INC/CEG/2/INF/3. 25 May
1999.
For further information contact:
World Wildlife Fund
1250 24th Street, NW
Washington DC, 20037-USA
Tel: 202/778-9625
Fax: 202/530-0743
Email: toxics@wwfus.org or
www.worldwildlife.org/toxics
United Nations Environment Programme Criteria
Expert Group for Persistent Organic Pollutants,
Second Session, Vienna, 14 - 18th June 1999,
Report of the second session of the Criteria Expert
Group for persistent organic pollutants.
UNEP/POPS/INC/CEG/2/3. 18 June 1999.
United Nations Environment Programme Criteria
Expert Group for Persistent Organic Pollutants,
Second Session, Vienna, 14 - 18th June 1999,
Submission by the Contact Group on Annex D,
Annex E, and Working Definitions.
UNEP/POPS/INC/CEG/2/CRP.14. 17 June 1999.
UNEP
Access their Web site at
http://irptc.unep.ch/pops/
Report of the second session of the Criteria Expert
Group for Persistent Organic Pollutants UNEP/POPS/INC/CEG/2/3
United Nations Environment Programme Criteria
Expert Group for Persistent Organic Pollutants,
Second Session, Vienna, 14 - 18th June 1999,
Submission by the Delegation of Denmark. Use of
QSARs for the selection of persistent organic
pollutants. UNEP/POPS/INC/CEG/2/CRP.4. 14
June 1999.
ENB:
Earth Negotiations Bulletins published by the
International Institute for Sustainable Development.
Access their Web site at http://www.iisd.ca.
Coverage of the second session of the POPs CEG
can be found at
http://www.iisd.ca/linkages/vol15/enb1512e.html.
18
Annex I
WWF Recommendations for POPs INC Delegates
On Criteria and Procedures for Adding New POPs to the Global POPs Treaty
1. Regional Scope of Coverage: Substances causing regional problems in several areas should be able to be covered under the
treaty, even if there is no proof of environmental transport on a global scale.
2. Organo-metals: Organo-metal compounds should be able to be added to the treaty in future.
3. Half-life in Water: The criterion of a half-life in water of greater than 2 months should be chosen in preference to a half-life
of greater than 6 months.
4. Log Kow of 4: For screening a log Kow value of 4 should be adopted in preference to a log Kow of 5.
5. Testing Programs: WWF Recommendation No. 5: Mandatory national and international testing programs should be
instigated to determine the ability of substances to bioconcentrate and persist in the environment. Such testing programs should
be tailored to determine whether substances meet the criteria necessary to be considered POPs under the treaty. To this end,
organizations such as the International Standards Organization (ISO) and the Organization for Economic Cooperation and
Development (OECD) should be encouraged to develop and improve relevant test methods.
6. Toxicity Screening Criteria-Part I: At the screening stage, comparison of toxicity or ecotoxicity data with actual or
predicted levels in far away locations should not be mandatory.
7. Toxicity Screening Criteria-Part II: The substance should be able to meet the screening criteria if it is believed to exert
effects via certain biochemical modes of action which give cause for concern. Regulatory action should not have to wait until
there are data showing that the substance has the potential to exceed, in the remote environment, the levels currently known to
cause damage to human health or the environment.
8. Toxicity Screening Criteria-Part III: At the screening stage, even in the absence of convincing toxicological data, a
substance should be able to meet the criteria if adverse social or economic impacts have occurred due to concerns about the
toxicity of the substance.
9. Precautionary Approach: The precautionary approach should relate to all decisions taken as to whether or not a proposed
substance meets the screening criteria and the requirements for listing under the treaty, and the risk management objectives of
the treaty. It should therefore be stated in the main body of the treaty text, in addition to being in the preamble.
10. Lack of Data/Worst Case: After an appropriate time period lack of data should be dealt with by using the worst case
scenario.
11. Non-party Suggestions on Substances: Governments should put in place mechanisms to enable members of the public
and public interest/environmental groups to make suggestions as to potential candidate substances for nomination.
12. Missing Data: If a proposal to list a substance does not contain the information required at the screening stage, the
Secretariat should inform all the Parties and observers and indicate which data were missing in order that assistance can be
provided in filling the data gaps.
13. Transparency: At all stages in the process of establishing whether or not a proposed substance should be listed under the
treaty, there should be full transparency of the decision making process. A summary of the reasons for the decisions taken, or
recommendations made by the POP Review Committee, and all written documentation supporting such decisions or
recommendations should be available to Parties, observers, and the public. When available, the report to the COP (making a
recommendation as to whether or not the substance should be considered for listing under the treaty), should be communicated
to all Parties and observers.
14. Socioeconomic Factors: Socioeconomic factors are important for determining appropriate time scales for the elimination
of a POP, but should be given consideration only after the evaluation stage has determined that the substance is a candidate
POP under the treaty.
20
Global Toxics Initiative
The overall goal of the Global Toxics Initiative (GTI) is to end the production, release, and use of
chemicals that are endocrine disruptors, bioaccumulative, or persistent within one generation – by no
later than 2020. GTI consists of three interrelated components: Wildlife and Contaminants, Persistent
Organic Pollutants (POPs), and Agriculture Pollution Prevention. While each three components have
unique characteristics, they are all closely linked. Many POPs are endocrine disruptors and several
pesticides are both endocrine disruptors and POPs. The main difference among the three components is
in their approach to the global problem of toxic chemicals –
 The POPs program centers its work on policy development and advocacy, such as aiming for the
phaseout and elimination of the most deadly, persistent pollutants like DDT, PCBs, and dioxins.
 The Wildlife and Contaminants program (WCP) focuses on the evolving science of endocrine
disruptors and other toxic substances.
 The Agriculture Pollution Prevention (APP) program, in collaboration with farmers and growers,
promotes integrated pest management (IPM) and other ecologically-sound alternatives to the use of
pesticides.
The Global Toxics Initiative is one of several initiatives that WWF has launched to address global threats
to the Earth’s environment posed by unsustainable timber trade, overexploited fisheries, profligate used
of toxic chemicals that harm wildlife, and unrestrained emissions of greenhouse gases that contribute to
global warming.
Addressing global threats is one of the three strategies pursued by WWF in its Living Planet Campaign—
a call to action to make the close of this century and the opening of the next a turning point in the
worldwide struggle to safeguard the critically endangered species, conserve endangered spaces—the
world’s most important harbors of biological diversity that WWF calls the Global 200, and encourage
changes in international policies and markets that contribute to environmental threats. To learn more
about WWF’s Global Toxics Initiative, visit our Web site at: http://www.worldwildlife.org/toxics.
World Wildlife Fund
1250 24th Street, NW
Washington, DC 20037
www.worldwildife.org
This publication was made possible through the
generous support of the Jenifer Altman Foundation.
Printed on recycled chlorine-free paper